if __name__ == "__main__":
    X = int(input())
    if X >= 30:
        print('Yes')
    else: 
        print('No') if __name__ == "__main__":
    X = int(input())
    if X >= 30:
        print('Yes')
    else: 
        print('No') __name__ == "__main__" __name__ "__main__" X = int(input()) X int(input()) int input() input if X >= 30:
        print('Yes')
    else: 
        print('No') X >= 30 X 30 print('Yes') print 'Yes' print('No') print 'No' X = int(input()) int(input()) X
if __name__ == "__main__":
    X = int(input())
    if X >= 30:
        print('Yes')
    else: 
        print('No')